Stewart Butterfield.

Stewart Butterfield is the Co-Founder and former CEO of Slack, the workplace messaging platform that fundamentally changed how teams communicate and collaborate.

Butterfield co-founded Slack in 2013, growing it into one of the fastest-growing enterprise software companies in history before Salesforce acquired it for $27.7 billion in 2021-one of the largest enterprise software acquisitions ever. Slack has over 30 million daily active users and has become synonymous with workplace communication, effectively replacing email for internal team interactions at thousands of companies. Before Slack, Butterfield co-founded Flickr, the pioneering photo-sharing platform that Yahoo acquired in 2005. Both Slack and Flickr emerged as pivots from failed video game projects, making Butterfield one of the most successful "pivot" entrepreneurs in technology history. Born in Canada, he holds a master's degree in philosophy from Cambridge. His ability to create two category-defining products-both born from failed game projects-and his thoughtful approach to product design and company culture have made him one of the most admired entrepreneurs in technology.